Liquid gas suitable for illuminating and heating purposes and method of making said gas.



L. WOLF. LIQUID GAS SUITABLE FOR ILLUMINATING AND HEATING PURPOSES AND METHOD OF MAKING SAID GAS.

APPLIGATION FILED OCT. 1, 1908.

Patented July 20, 1909.

UNITED strarrps PATENT OFFICE. i

LINUS WOLF, OF BOSTON, MASSACHUSETTS.

LIQUTD GAS SUITABLE FOR ILLUMINATING AN'iD HEATING PURPOSES AND METHOD OF MAKING SAID GAS.

Application filed October 1, 1908. Serial No. 465,707.

Specification of Letters Patent.

Patented July 20, 1909.

To all whom 'it may concern:

Be it known that I, Linus \Vonr, a subject of the Emperor of Germany, residing at Boston, county of Suffolk, and State of Massachusetts, have invented an Improvement in Liquid Gas Suitable for Illuminating and Heating Purposes and Methods of Making said Gas, of which the following description, in connection with the accompanying drawing, is a specification, like figures on the drawing representing like parts.

This invention relates to the production of an illuminating and heating gas in liquefied form.

One of the objects of the invention is to providcanew liquefied gas which is capable of being manufactured from crude oil, petroleum, bitumen, natural gas, and other raw material; which when put under a pressure of three or four or less atmospheres atnormal temperature will rapidly assume the gaseous form without leaving any liquid residue; which can be safely transported in its liquefied form; and the vapor of which is non-poisonous and can be safely used for either illuminating or heating purposes.

Another object of the invention is to provide a novel and inexpensive method of manufacturing such a gas from raw material.

The distillation vapors produced by the dry distillation of crude oil, petroleum, bitumen, and similar raw material, contain hydrogen and hydrocarbons of the methane, ethylene. acetylene, and other series beginning with those above mentioned members and rising to, those of a higher carbon content and a correspondingly higher boiling point. These hydrocarbons may be for convenience roughly divided into the following four classes:

Class v1. Those substances which are in solids or in liquid form at ordinary temperatures and the boiling point of which is well above ordinary temperature. This class is represented by most of the petroleum products of commerce, such as kerosene, lubricating oils, Vaseline, paraffin, tar, etc.

Class 2. Those substances boiling at or near ordinary temperature, including those that are readily liquefied by moderate cooling or slight pressure. Examples'of this 1 class are gasolene, benzin, naphtha, and other easily-vaporizable liquid hydrocarbons.

Class'3. Those substances which are gaseous at ordinary temperature and pressures but which can be liquefied by vigorous refrigeration or by moderate refrigeration, and

the application of pressure. Examples of this class are acetylene, propane, pentane etc.

Class 4. Those gases which can be lique-f fied only by extremely high pressure in connection with'excessively high refrigeration. Examples of this class are hydrogen, methane, etc, gases which because of the difficulty with which they can be liquefied are commonly referred to as permanent gases.

It should be remembered that the above is merely a rough classification and that there is no sharp line between the different classes, but that, on the other hand, they graduate imperceptibly into eachother.

My new liquefied gas is one secured, first, by removing as completely as possible from the distillation products of crude oil petro-- leum, bitumen, or other suitable raw materials, or from natural gas, those substances belonging to Classes 1 and 2 as above described; second, by liquefying as completely as possible those substances belonging to Class 3; third, by condensing the remaining unliquefied portions of Class 3 and causing them to be mixed with the liquefiedgas; and lastly, separating the excess of the substances of Class 4. The new product which I 'thus obtain is a true liquefied gas which, if at ordinary temperature, the pressure upon it be lessened to not more than a few atmos' pheres (four to five) will rapidly and completely assume the gaseous form without leaving any liquid residue.

In manufacturing a liquefied gas of this character from raw material, such, for instance, as heavy oil, paraflin oil, crude petroleum, bitumen, etc., I first distil such raw material to obtain therefrom distillation gases, and after separating or condensing therefrom those substances, such-as tar, belonging generally to Class 1 above described, the distillation gases are treated to eliminate. all those constituents which belong generally to Class 2 and which comprise the easilyvaporizable liquid hydrocarbons. This step in the process can conveniently be done by chilling or cooling the gases to a marked dedue when the liquefied gas is vaporized.

gree, as-would be the case if they were cooled to 25 C. to 30 C., the chilling of the gases to this-point ,resulting in converting into liquid form the constituents represented by Class 2. The gas remaining after eliminating the above-described liquefiable constituents is then further treated so as to liquefy those constituents represented by Class 3, and the excess permanent gases are then separated from the product, thus leaving a liquefied gas embodying the invention.

While it is possible to secure the separation of the permanent gases from the liquefied gas in various ways, I prefer to accoml5 plish this by forcing the gas while at a low temperature into a body of gasolene. for I. find that where this procedure is adopted, the permanent gases are more easily separated from the liquefied gas and at-the same 2 time any heavy liquefiable hydrocarbons which would naturally be carried off with the permanent gases are washed out from the gases by the gasolene and are thus lique fied and added to the body of liquefied gas 5 from which the permanent gases are separated. During this latter process some small amount of the gasolene. into which the liquefied gas is forced becomes mixed with cthe'product but the amount of gasolene thus mixed is so small that it is gaseous at ordinary temperatures even under several atmos pheres pressure and therefore the presence of this small amount of gasolene does not result in the production of any liquid resi- It is possible to treat natural gas according to this same method and to produce therefrom a liquefied gas capable of being used successfully in heating and illuminating.

My-invention can be explained more in detail by referring to the accompanying drawings which are illustrative of the character of an apparatus which may convenientl'y be adopted to carry out my method, 5 it being understood that the method is not confined to the use of the apparatus herein shown, but may be carried outby other up paratus, and also that the device herein'illus- C trated is not essential for the production of the resultant product. In the apparatus herein shown the desired low temperature of the gas is secured either by the expansion of some of the highly compressed or liquefied gas, or by the expansion of some of the gasolene which is under a heavy pressure. The gas is cooled in this way partly because a greater'cooling effect can be produced than is possible with ordinary Water-cooling processes, and partly because it is more economical to cool the gas in this way than by other known processes.

Referring now to the drawings wherein I have shown for the purpose of illustration R an apparatus capable of carrying out the process, igure 1 is a diagrammatic view of the apparatus as a whole, and Fig. 2 is a detail hereinafter referred to.

The apparatus herein shown includes a distilling device which is used where the raw products to be used in making the lamefied gas are crude oil, bitumen, etc. When the liquefied gas is to be made from natural gas, this distilling device will not be necessary. The distilling device comprises a retort 1 having therein a pan or receptacle in which the oil or other product to be vaporized is received. This retort is arranged to be heated by a suitable furnace 71 and the temperature of the furnace may conveniently be controlled by any usual or suitable thermostat which is shown more or less diagrammatically at- 7 2. The retort is supplied with oil in any usual way as, for 111- stance, by providing a pipe 15 leading into the retort, which in turn is supplied with Oll from a tank 14. A pump 12 connected to the tank by a supply pipe 13 serves to keep the tank filled with oil from a main supply 11. The retort has connected thereto a pipe 18 through which the oil vapor or distillation gas formed in the retort is delivered to a taxik 3 in which the tar and other similar heavy products belonging to Class 1 above eferred to are condensed and accumulate. Such products may. be drawn off from tune 'to time through the valve 9. The tank 3 has connected thereto a pipe 20 leading to a gascooling apparatus which is capable of cool ing the gas to a marked degree. In fact, I have found from experiments that the gas enters the cooling apparatus at about 125 C. and emerges from the cooling apparatus at about 25 C. This cooling apparatus comprises a central chamber 21 into the lower end of which the pipe 20 leads and which is inclosed within a casing 22 that is surrounded by a covering 23 of insulating material. The central chamber 21 is open at its bottom and cbmmunicates with a closed tank or chamber 89 which is provided with the valve 90. The distillation gases passing up through the chamber 21 are rapidly cooled to a comparatively low temperature, as above specified, and during such cooling process those hydrocarbon constituents of the distillation gases which belong to Class 2 as above defined, and which comprise the easily-vaporizable liquid hydrocarbons are condensed or liquefied and accumulate in the tank 89 from which they may be removed from time to time through the valve 90. The upper end of the chamber 21 is connected by a pipe 26 with a gas purifier 4 which is for the purpose of removing from the gas any sulfureted hydrogen, and other impurities. The purifier is connected by a pipe 27 with a compressor 6 and also by a pipe 33 with a gasometer 8, this gasometer acting as a balance in usual manner. The compressor is also connected bya pipe 32 th t a -s pa a ng appara u whic a clOSed chamber adapted to contain gasolene, petroleum, or other oil, and while the chamber may have any appropriate shape, I haye herein shown it in the form of two spiral or serpentine coils 7 which are connected together at the bottom and which are both connected to a chamber at the top. The pipe 32 leads into the lower ends of the coils, as shown in Fig. 2, and is branched within the coils, as 31147 48, the two branches extending a short distance above the bottom ofthe coils. The lower end of the coils is connected by a ipe 46 with the tank 45 into which .the liquefied gas is to be stored.

78 .is a tank or chamber adapted to hold gasolene, petroleum or other oil which is used in .the coil 7, said tank being connected to the chamber 30 by means of a pipe 79 having a valve .62 therein.

29 is a .pump arranged to force the gasolene ,from the tank 78 into the chamber 30. Communication between the chamber 30 and the coils 7 can be controlled by means of two valves 61. My improved process is carried out by means of the above-described apparatus in the following manner: The distillation gases which are produced in the retort 1, or the natural; gas from which the product is to be made, are first carried over through the pipe 18 into the tank 3, at which point the tar and other similar heavy products be- -'longing to Class 1- as above defined are con densed and removed from the gas. The gas passes from the tank 3 .to the chamber 21 of the cooling apparatus where its temperature is reduced to approximately 25 C. to -80 C. As stated above, during this cooling process, those constituents of the distillation gas which belong generally to Class 2 as above defined, .that is, those constituents which will liqu'efy'at atmospheric pressure and a temperature to which the gas-is cooled,

become liquefied and drain into the tank 89,

and ,thus become separated fromthe other constituents belonging generally to Classes 3 and 4 as above defined. The constituents thus separated have the general characteristics of gasolene and include all the easilyvaporizable liquid hydrocarbons. The remaining cooled gas passes while still at its low temperature into and through the purifier 4 wherein the noxious and poisonous gases,"such as sulfureted hydrogen, etc. are

removed, without, however, appreciably increasing-the temperature of the gas. The

gas while still cool passes to and through the compressor 6 which is arranged to compress it to approximately 1500 pounds to the square inch. The heat of compression gen- .e a e .int he .cqmpres q may e semer d is a y su tab t y, a y Water a n th compressor. The compressed gases are then delivered to the closed chamber which has p vi usly e p r y fille wit ga o n or some other petroleum oil, the gasolene preferably ,filling the coils ,7 slubstantially to the top thereof. During the operation ,the valves 62 and 64-are closed. The compression of the cooled gas to .1500 pounds resu ts in liqueiying substantially all the constituents except the permanent gases, such as methane and hydrogen, that is, such compression results in liquefying substantially all the constituents of Class 3 as above defined, while leaving the constituents belonging to Class 4 still in gaseous form.

When liquefied gas thus obtained is at a low temperature and manent'gases, however, tend to carry with them certain proportion of the heavy hydrocarbon constituents belonging to Class 3,

. and which are capable of being liquefied, and

as such permanent gases with the liquefiable hydrocarbon constituents pass up through the gasolene, petroleum, or other 011 in the chamber 7, such hydro-carbon constituents are washed out of the permanent gases by the gasolene, petroleum or other 011, and unite with the liquefied constituents at the bottom of the coils 7 During th1s washing process possibly a certain small proportlon of the gasolene or petroleum mixes with the hydrocarbons that are washed out of the permanent gases, and such small proportion of the gasolene becomes mixed with the liquefied gas. The liquefied gas which accumulates atthe bottom of the coils is drawn oil into the tank 45 through the pipe 46 'in usual manner. The product which is drawn off in the .tank 45 is a liquefied gas formed by liquefying those constituents of distillation' gas, or natural gas, which are left after the more easily liquefiable constituents belonging to .Class 2 and the permanent gases belonging to Class 4are removed. The hquefied gas thus obtained comprises principally ethane and ethylene .and the next higher homologues of ethane, although a careful analysis of the gas shows that it has a small trace of methane and sometimes a small portant feature because the presence of .8,

- resi liquid residue in the tank is a source of great danger owing to the fact that such liquid ue will gradually vaporize and thus form a very explosive mixture. The vapor formed" from the liquefied gas above described is capable of developing an extremely high heat when burned under proper conditions and is also an extremely good illuminant. The gas produced from the vaporization of the liquid is non-poisonous and is much less likely to form an explosive mixture with air than is acetylene or ordinary illuminating gas.

My improved method also includes a novel .way of cooling'the gases before they pass to the purifier. by which the extremely low temperature of C. to C. can

pipe having therein an ordinary reducing by this expansion of the valve 25. Another pipe 80 connects the lower end of the casing 22 with the tank 78 w and still another pipe 81 connects the casing 22 at a point below itsuppe end with the pipes 27 and 33. The pipe 24 is preferably connected to the coil 7 at a point slightly above the division line between the liquid gas and the gasolene or petroleum. It will be understood that during the operation of the apparatus the gasolene in the coil 7 is subjected to the high pressure developed by the compressor and a portion of this compressed gasolene which has some of the liquefied gas constituents associated therewith .escapes through the reducing valve 25 and expands and vaporizes within the casing 22, thus cooling the chamber 21 and the gases passing up therethrough. The cooling effect which can thus be produced by the expanding gas is sufficient to reduce the temperature of the distillation gases to approximately 25 C. to -30 C. The vapors formed as are returned to the compressor through t e-pipe 81 while the gasolene liquid which is not vaporized or which is formed from the condensation of the vapor in the casing 22 is returned to the tank 78 through the p1pe80. This manner of cooling the gas I consider as an impor'tant feature of the process as it enables me to secure rapidly andat a minimum ex pense the extremelylow temperature. desired.

While the apparatus shown is such as could be used in liquefying distillation gases, the process can" also be used for producing my improved liquefied gas from natural gas.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent is 1. The process of producing a liquefied gas which consists in producing distillation gases, liquefying all such constituents thereof as will liquefy at atmospheric pressure and at a temperature of approximately 25 C. and which in liquid form include the easily-vaporizable liquid hydrocarbons, separating all the liquid thus obtained from the remaining constituents and liquefying all said remaining constituents except the permanent gases.

2. The process of producin a liquid gas from distillation gases whicir consists in cooling the distillation gases to approximately -25 (1., thereby to liquefy all those constituents which comprise the easily-vaporizable liquid hydro-carbons, separating the liquid thus obtained from the remaining constituents, and subjectin the remaining constituents to a pressure s1 cient to liquefy all the gases except the permanent gases.

3. The process of producing a liquid gas from distillation gases which consists in coo1- ing the distillation gases to approximately 25 (1, thereby to liquefy all those constituents' which comprise the easily vaporizable liquid hydro-carbons, separating the liquid thus obtained from the remaining constituents, and forcing all the remaining constituents into a chamber filled with gasolene under a pressure of approximately 1500 pounds.

4. A liquid gas which comprises liquefied hydrocarbon-constituents of dlstillation gases which are entirely free from those constituents which can be liquefied at atmospheric pressure and at a temperature of approximately 25 C.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

LINUS WOLF.

\Vitnesses BERTHA F. HEUSER, FREDERICK S. GREENLEAF. 

